Her husband, John, announced Monday that he would not seek another term.

"I'm not running to replace John Dingell. I think he's irreplaceable," she said of her husband, a Democrat who has held the seat for 58 years. "I want to keep fighting for the issues that have always been my passion, especially women and children."

Several dozen supporters joined Debbie Dingell, 60, at the Panera Bread in her hometown, the first of three stops to launch her campaign.

Dearborn Mayor Jack O'Reilly said Dingell is the best person to represent the district because of her breadth of knowledge of the cities and towns in the 12th Congressional District, which covers portions of western Wayne and Washtenaw counties.

"You have to know Washington and Washington needs to know you," he said. "We'll be sending a freshman to Washington. She should have the ability to be known and have access to departments."

While a poll released Friday by Inside Michigan Politics, a Lansing-based political newsletter, shows she has a large lead in a five-way Democratic primary, she won't have a clear shot at the seat that a Dingell has represented for the last 80 years. State Sen. Rebekah Warren, a Democrat from Ann Arbor, Mich., also announced Friday that she's forming an exploratory committee to examine a congressional run.

"So much of the work I've done at the state Capitol needs federal solutions and that would give me the chance to continue my state level work," Warren said. "And forming the committee gives me the only legal mechanism to do the research and talk to folks before I make the decision."

In the poll of 813 Democratic primary voters, Dingell got 51% of the vote, followed by Warren with 15.7%; 23% of those surveyed were undecided. The margin of error for the poll, which was taken earlier this week, was ±3.4 percentage points.

Dingell is half of one of Washington's most powerful political couples. She has been a member of the Democratic National Committee for years, is a member of the Wayne State University Board of Governors in Detroit and has had high-level positions with General Motors. She also ran Al Gore's presidential campaign in Michigan in 2000.

If she were successful, she would become the third Dingell in a row to represent a portion of southeast Michigan in Congress. John Dingell's length of service stretches back to a time before Alaska and Hawaii were states, when he won the seat after his father served in Congress for 22 years.

But Dingell said Friday that she won't be a John Dingell clone.

"Like any married couple, we don't agree on everything," she said. "But I know how to navigate the halls of Congress and I'll bring a fresh perspective."

One area of disagreement is gun control. John Dingell has been a loyal member of the National Rifle Association and has a solid voting record on fighting gun control efforts; Debbie Dingell has written opinion pieces about her support for stronger gun control laws.

The candidates have a little more than seven weeks to gather at least 1,000 valid signatures from voters in the district to qualify for the ballot.